Optical interconnection system for transmitting and receiving a three-level signal and method of operating the same

Abstract

Provided is an optical interconnection system that transmits and receives a three-level signal. The optical interconnection system includes a first and a second optical interconnection device that transmits and receives a two-level signal, and a synthesizer that outputs a three-level signal by synthesizing signals from the first and second optical interconnection devices. The optical interconnection system may transmit and receive a three-level signal while using an optical interconnection device that interconnects a two-level signal.

1. An optical interconnection system that transmits and receives a three-level signal, comprising:
 a first optical interconnection device and a second optical interconnection device, each of the first and second optical interconnection devices transmitting and receiving a two-level signal; and 
 a synthesizer that outputs a three-level signal by synthesizing signals received from the first and second optical interconnection devices, wherein each of the first and second optical interconnection devices includes,
 a light emitting unit driver to which an electrical signal is input; 
 a light emitting unit that emits a light from the light emitting unit driver; 
 an optical waveguide through which the light emitted from the light emitting unit is transmitted; 
 a light receiving unit that receives light transmitted by the optical waveguide and outputs a current based on the received light; and 
 a light receiving unit driver that outputs a voltage signal in response to the current received from the light receiving unit. 
 
 
     
     
       2. The optical interconnection system of  claim 1 , further comprising:
 a distributor that distributes an externally received electrical signal to the light emitting unit driver of the first optical interconnection device and the light emitting unit driver of the second optical interconnection device. 
 
     
     
       3. The optical interconnection system of  claim 2 , wherein
 a signal input to the light emitting unit driver of the first optical interconnection device from the distributor is output as a high level signal from the first optical interconnection device; and 
 a signal input to the light emitting unit driver of the second optical interconnection device from the distributor is output as a low level signal from the second optical interconnection device. 
 
     
     
       4. The optical interconnection system of  claim 2 , wherein the distributor divides the external electrical signal into a first reference voltage and a second reference voltage, and supplies the first reference voltage to the first optical interconnection device and supplies the second reference voltage to the second optical interconnection device. 
     
     
       5. The optical interconnection system of  claim 4 , wherein the first reference voltage is higher than a threshold voltage of the light emitting unit driver of the first optical interconnection device and the second reference voltage is lower than a threshold voltage of the light emitting unit driver of the second optical interconnection device. 
     
     
       6. The optical interconnection system of  claim 1 , wherein at least one of the light emitting units of the first and second optical interconnection devices is a vertical cavity surface emitting laser (VCSEL) emitting an infrared light, and at least one of the light receiving units of the first and second optical interconnection devices is a photodiode detecting the infrared light. 
     
     
       7. A method of operating an optical interconnection system for transmitting and receiving a three-level signal, the method comprising:
 transmitting and receiving a two-level signal using a first and a second optical interconnection device; 
 providing an output of each of the first and second optical interconnection devices to a synthesizer; and 
 synthesizing the output of each of the first and second optical interconnection devices to output a three-level signal, wherein 
 the transmitting and receiving includes,
 inputting an electrical signal to a light emitting unit driver, 
 emitting light from the light emitting unit driver, 
 transmitting the emitted light through an optical waveguide, and 
 receiving the transmitted light using a light receiving unit, and 
 
 the providing includes,
 outputting a current based on the received light, and 
 outputting a voltage signal in response to the received current. 
 
 
     
     
       8. The method of  claim 7 , further comprising:
 distributing an externally received electrical signal to the respective light emitting unit drivers of the first and second optical interconnection device. 
 
     
     
       9. The method according to  claim 8 , wherein
 the electrical signal distributed to the light emitting unit driver of the first optical interconnection device is output as a high level signal; and 
 the electrical signal distributed to the light emitting unit driver of the second optical interconnection device is output as a low level signal. 
 
     
     
       10. The method according to  claim 8 , wherein distributing includes,
 dividing the external electrical signal into a first reference voltage higher than a threshold voltage of the light emitting unit driver of the first optical interconnection device and a second reference voltage lower than a threshold voltage of the light emitting unit driver of the second optical interconnection device, and 
 supplying the first reference voltage to the first optical interconnection device and the second reference voltage to the second optical interconnection device.